A. Field of the Invention
The present invention relates generally to plant-based dyes and processes for making such dyes. In particular, the present invention relates to dyes made from tobacco plant materials and processes for making such dyes. Even more particularly, the present invention relates to such processes that are utilized to produce dyes from tobacco plants in an environmentally-friendly and efficient manner.
B. Background
Plant fiber materials have been utilized for many years to produce textile from which a wide variety of fabrics can be manufactured. In particular, it has been known for many years that the bast fibers of various plants, including hemp, flax, jute, nettle, ramie and the like, can be utilized for a wide variety of different textiles. The bast fibers grow on the outside of the woody core of the plant's stalk, referred to as the xylem, and under the outer most part of the plant (e.g., the bark). These fibers give the plant strength and support the conductive cells of the phloem, the layer of the plant just under the bast fibers and in which the valuable fibers are located. The bast fibers of the typical plant are attached to the wood core fibers by the combination of pectin, a glue-like substance, and calcium ions. In order to beneficially use the bast fibers, however, they must be separated from the rest of the stalk. Typically, the separation of the bast fibers from the woody core is accomplished utilizing a procedure commonly referred to as retting, which is a process of rotting away the inner plant stalk to leave the outer bast fibers intact. Retting is accomplished by micro-organisms either on land or in the water or by using chemicals or pectinolytic enzymes.
The most common method of retting comprises placing the plant material to be retted in a pond, stream, field or tank and exposing the material to water for a sufficient amount of time to allow the water to penetrate the central stalk portion, swell the inner cells and burst the outermost layer, thereby exposing the inner core to decay-producing bacteria that will rot away the inner stalk and leave the outer fibers intact, a procedure known as decortification. As well known in the art, the retting process results in several environmental issues, primarily the production of chemical compounds that can cause pollution if the waste water is not properly treated and odors. Although pond and stream retting, which requires the plant material to be submerged in the pond or stream, tend to be the fastest methods of retting they also tend to produce the most pollution. Field retting, which involves laying the plant material out in a large field and allowing dew to collect on it, takes considerably more time but tends to produce less pollution. Tank retting typically provides greater control over the process, in which concrete vats or the like are commonly utilized as the tank, but it also produces significant toxic elements in the waste water that must be treated prior to being released to the environment. In some processes, sulphur and other toxic chemicals are introduced into the system to speed up and more effectively accomplish the process of separating the bast fibers from the wood core of the plant stalk.
As well known by those familiar with textiles (as well as many other products), there has been an increase in demand for products that are made from natural materials and for products that are produced in a more environmentally friendly or “green” manner so as to reduce negative impacts on the environment. Products which are both made from natural products and in an environmentally friendly manner are particularly desired. With regard to plants, whether utilized for their fiber or as a food source, there has been a significant increase in the demand for naturally or organically grown products. One common feature of producing such products is that they are grown with no or at least a significantly reduced amount of chemical fertilizers, pesticides and other products. Many consumers desire organically grown products because they substantially lessen the likelihood of pollutants from runoff and groundwater penetration, significantly reduce the overall “carbon footprint” by not requiring the production, delivery and application of chemicals to the land and/or plants and do not place dangerous and potentially harmful chemicals into the food chain. The use of natural plant materials for textiles has benefited generally from the increase in the desire for natural products. Unfortunately, although the use of natural plant materials for textiles does have the benefit of being organic, including being able to be grown under organic conditions, the retting process of treating the plants to separate the desirable bast fibers for use to make the textiles is not generally considered to be organic or environmentally friendly.
One plant which has not been heretofore utilized for the production of textiles is the tobacco plant, which are plants in the genus Nicotiana. There are many species of tobacco plants that fall within the genus of herbs Nicotiana, all of which are collectively referred to as tobacco plants. Although the leaf of the tobacco plant has a long history of use in the United States and elsewhere for smoking, chewing and snuff tobacco products, it is believed that the plant fibers have never been utilized to form textiles or any textile-related products, perhaps due in part to the high value of the leaf of the plant for use in the manufacture of tobacco products. The leaves of the tobacco plant are also utilized as an organic pesticide and in some medicines. Unlike such plants as hemp and nettle, where it is primarily the stalk of the plant that is commercially beneficial (except for some use of the leaves as a tea or food item), the tobacco plant is primarily only grown for its leaves. For consumption as cigarettes and other smoking products, the tobacco plants are often fertilized with the mineral apatite to starve the plant of nitrogen and produce a more desired flavor. The mineral apatite, however, contains radium, lead and other compounds that are known to be radioactive carcinogens. After the leaves are harvested from the tobacco plant, they are cured and aged to allow for the slow oxidation and degradation of the carotenoid in the tobacco leaf. The production of tobacco plants for tobacco products are known to require the use of a relatively large amount of fertilizers and pesticides, which frequently end up in waterways and the food chain. The typical curing process requires a large amount of fuel, typically petroleum, coal and natural gas. Many areas of the world that do not have sufficient access to these fuel sources utilize a large amount of wood for the curing of the tobacco leaves, which is known to be a contributing factor to deforestation.
The use of tobacco, particularly in the form of cigarettes and other smoking products, is known to cause a variety of health issues, including cancer, that can lead to death. As a result of the health issues associated with use of tobacco products, the availability of such products is limited to persons over the age of eighteen in the United States. In addition, many government and other organizations actively and strongly encourage people to quit using such tobacco products through public service announcements and the imposition of taxes that are directed solely at tobacco products. Smoking and other uses of tobacco are banned in most public and work places. Due to the various negative health, cost, convenience and other issues related to the use of tobacco products, their use has significantly decreased over the years. This decrease in use is anticipated to continue over time. As a result, there is likely to be excess production capacity for tobacco plants that will allow its economical use as a natural textiles, dyes and other products. Presently, however, there is no known process for converting the otherwise harmful tobacco plant into a textile, dye or other useful product that is efficient, economical and environmentally-friendly.
Dyes for changing the color of fibers and the like are known to have been in use for many thousands of years. Dyes can be made from a variety of sources, including animal, plant and mineral materials. The most common form of dyes originate naturally as plants, typically the berries, roots, bark, leaves and wood portions thereof. Natural dyes are also known to be made from fungi and lichens. Although dyes were commonly made from these and other natural products, currently dyes are generally synthetically produced from a wide variety of different chemicals. In fact, from a commercial standpoint, natural dyes are rarely produced in large-scale quantities. When produced, natural dyes require the use of a mordant to improve the fastness of the dye and to protect against color degradation due to water, light and perspiration. As well known, mordants are utilized to set a dye on a fibers, fabrics and other materials and accomplish this objective by forming a coordination complex with the dye that then attaches to the material to be dyed. One concern with regard to mordants is that the selection of a mordant for a particular coloring use is critical, as the final color of the material to be dyed can be highly affected by the choice of the mordant. In addition, most mordants contain heavy metals, which are known to be hazardous to persons and harmful to the environment if the mordant is not properly stored, handled or disposed. In light of the problems associated with mordants, there is a desire for a natural dye that can be readily, efficiently and relatively cheaply produced and which can be utilized without a mordant.
What is needed, therefore, is a dye that is made from tobacco plant materials and a process for efficiently and effectively transforming these materials into dyes and other useful products. Preferably, the dye should be made from one or more components of the tobacco plant. The preferred process for making a tobacco-based dye should be adaptable for utilizing organically grown tobacco plants and be able to produce dyes and other useful products from such plants in an efficient, economical and environmentally-friendly manner. Preferably, the process for making dye from tobacco plants should be selected so as to not contaminate the environment and/or not result in health problems for those utilizing the process.